Multiple loop tissue connector apparatus and methods

ABSTRACT

A tissue connector assembly comprising a multiple loop fastener movable between an open configuration and a closed configuration and a restraining device attached to the fastener for restraining the fastener in its open configuration provides for a self-closing, multiple suture fastener. A needle may be releasably attached to the fastener. A method for connecting tissues is also disclosed. The method includes inserting a fastener through tissue with the fastener being biased in an open position by a restraining device secured to the fastener, threading the fastener through more than one stitch, and removing the restraining device from the fastener.

CROSS-REFERENCE TO RELATED DOCUMENTS

The present application is a continuation-in-part of patent applicationsSer. No. 09/090,305, filed Jun. 3, 1998, now U.S. Pat. No. 6,641,593 andSer. No. 09/260,623, filed Mar. 1, 1999, now U.S. Pat. No. 6,613,059.

FIELD OF THE INVENTION

The present invention relates to instruments and methods for connectingbody tissues, or body tissue to prostheses.

BACKGROUND OF THE INVENTION

Minimally invasive surgery has allowed physicians to carry out manysurgical procedures with less pain and disability than conventional,open surgery. In performing minimally invasive surgery, the surgeonmakes a number of small incisions through the body wall to obtain accessto the tissues requiring treatment. Typically, a trocar, which is apointed, piercing device, is delivered into the body with a cannula.After the trocar pierces the abdominal or thoracic wall, it is removedand the cannula is left with one end in the body cavity, where theoperation is to take place, and the other end opening to the outside. Acannula has a small inside diameter, typically 5-10 millimeters, andsometimes up to as much as 20 millimeters. A number of such cannulas areinserted for any given operation.

A viewing instrument, typically including a miniature video carmera, oroptical telescope is inserted through one of these cannulas and avariety of surgical instruments and refractors are inserted throughothers. The image provided by the viewing device may be displayed on avideo screen or television monitor, affording the surgeon enhancedvisual control over the instrunents. Because a commonly used viewinginstrument is called an “endoscope,” this type of surgery is oftenreferred to as “endoscopic surgery.” In the abdomen, endoscopicprocedures are commonly referred to as laparoscopic surgery, and in thechest, as thoracoscopic surgery. Abdominal procedures may take placeeither inside the abdominal cavity (in the intraperitoneal space) or ina space created behind the abdominal cavity (in the retroperitonealspace). The retropcritoneal space is particularly useful for operationson the aorta and spine or abdominal wall hernia.

Minimally invasive surgery has virtually replaced open surgicaltechniques for operations such as cholecystectomy and anti-refluxsurgery of the esophagus and stomach. This has not occurred in eitherperipheral vascular surgery or cardiovascular surgery. An important typeof vascular surgery is to replace or bypass a diseased, occluded orinjured artery. Arterial replacement or bypass grafting has beenperformed for many years using open surgical techniques and a variety ofprosthetic grafts. These grafts are manufactured as fabrics (often fromDACRON® (polyester fibers) or TEFLON® (fluorocarbon fibers)) or areprepared as autografts (from the patient's own tissues) or heterografts(from the tissues of animals) or a combination of tissues, semisynthetictissues and or alloplastic materials. A graft can be joined to theinvolved artery in a number of different positions, includingend-to-end, end-to-side, and side-to-side. This attachment betweenartery and graft is known as an anastomosis. Constructing an arterialanastomosis is technically challenging for a surgeon in open surgicalprocedures, and is almost a technical impossibility using minimallyinvasive techniques.

Many factors contribute to the difficulty of performing arterialreplacement or bypass grafting. See generally, Wylie, Edwin S. et al.,Manual of Vascular Surgery, (Springer-Verlag New York), 1980. One suchfactor is that the tissues to be joined must be precisely aligned withrespect to each other to ensure the integrity and patency of theanastomosis. If one of the tissues is affixed too close to its edge, thesuture can rip through the tissue and impair both the tissue and theanastomosis. Another factor is that, even after the tissues are properlyaligned, it is difficult and time consuming to pass the needle throughthe tissues, form the knot in the suture material, and ensure that thesuture material does not become tangled. These difficulties areexacerbated by the small size of the artery and graft. The arteriessubject to peripheral vascular and cardiovascular surgery typicallyrange in diameter from several millimeters to several centimeters. Agraft is typically about the same size as the artery to which it isbeing attached. Another factor contributing to the difficulty of suchprocedures is the limited time available to complete the procedure. Thetime the surgeon has to complete an arterial replacement or bypass graftis limited because there is no blood flowing through the artery whilethe procedure is being done. If blood flow is not promptly restored,sometimes in as little as thirty minutes, the tissue the artery suppliesmay experience significant damage, or even death (tissue necrosis). Inaddition, arterial replacement or bypass grafting is made more difficultby the need to accurately place and space many sutures to achieve apermanent hemostatic seal. Precise placement and spacing of sutures isalso required to achieve an anastomosis with long-term patency.

Highly trained and experienced surgeons are able to perform arterialreplacement and bypass grafting in open surgery using conventionalsutures and suturing techniques. A suture has a suture needle that isattached or “swaged on” to a long, trailing suture material. The needlemust be precisely controlled and accurately placed through both graftand artery. The trailing suture material must be held with propertension to keep the graft and artery together, and must be carefullymanipulated to prevent the suture material from tangling. In opensurgery, these maneuvers can usually be accomplished within thenecessary time frame, thus avoiding the subsequent tissue damage (ortissue death) that can result from prolonged occlusion of arterial bloodflow.

The difficulty of suturing a graft to an artery using minimally invasivesurgical techniques has effectively prevented the safe use of thistechnology in both peripheral vascular and cardiovascular surgicalprocedures. When a minimally invasive procedure is done in the abdominalcavity, the retroperitoneal space, or chest, the space in which theoperation is performed is more limited, and the exposure to the involvedorgans is more restricted, than with open surgery. Moreover, in aminimally invasive procedure, the instruments used to assist with theoperation are passed into the surgical field through cannulas. Whenmanipulating instruments through cannulas, it is extremely difficult toposition tissues in their proper alignment with respect to each other,pass a needle through the tissues, form a knot in the suture materialonce the tissues are aligned, and prevent the suture material frombecoming tangled. Therefore, although there have been isolated reportsof vascular anastomoses being formed by minimally invasive surgery, nosystem has been provided for wide-spread surgical use which would allowsuch procedures to be performed safely within the prescribed timelimits.

As explained above, anastomoses are commonly formed in open surgery bysuturing together the tissues to be joined. However, one known systemfor applying a clip around tissues to be joined in an anastomosis isdisclosed in a brochure entitled, “VCS Clip Applier System”, publishedin 1995 by Auto Suture Company, a Division of U.S. Surgical Corporation.A clip is applied by applying an instrument about the tissue in anonpenetrating manner, i.e., the clip does not penetrate through thetissues, but rather is clamped down around the tissues. As previouslyexplained, it is imperative in forming an anastomosis that tissues to bejoined are properly aligned with respect to each other. The disclosedVCS clip applier has no means for positioning tissues. Before the clipcan be applied, the tissues must first be properly positioned withrespect to each other, for example by skewering the tissues with aneedle as discussed above in common suturing techniques or with forcepsto bring the tissues together. It is extremely difficult to perform suchpositioning techniques in minimally invasive procedures.

Therefore, there is currently a need for other tissue connectorassemblies.

SUMMARY OF THE INVENTION

The present invention involves improvements to devices and methods forconnecting tissues or tissue(s) and grafts, such as in a vascularanastomosis. The invention generally involves a surgical clip orfastener which is self-closing. Preferably, the surgical fastenercomprises a shape memory material, most preferably nitinol.

According to one aspect of the invention, a tissue connector assembly isprovided with a self-closing fastener movable between an openconfiguration and a closed configuration, and a restraining deviceattached to the fastener for restraining the fastener in its openconfiguration. The fastener may have a generally U-shaped configurationwhen in its open configuration. In one embodiment the restraining devicecan be uncoupled from the fastener, allowing the fastener to move froman open towards the closed configuration.

According to another aspect of the present invention, the fastener hasone or more needles releasably attached to the fastener. In oneembodiment the fastener is releasably coupled to one needle, and in asecond embodiment the fastener is releasably coupled to two needles. Inparticular, each fastener end can have a separate release mechanism forreleasing a needle.

According to yet another aspect of the present invention, the fasteneris a wire that is held in an open configuration with a restrainingdevice comprising a coil wrapped about the wire.

According to an aspect of the present invention, a fastener is providedfor forming multiple stitches. In one embodiment, the fastener has anopen and a closed configuration. The fastener in an open configurationcan be threaded through multiple stitches through tissue. When thefastener is returned to a closed configuration, the fastener provides aclosing force to the stitched tissue. In another embodiment the fastenerhas a restraining device and is attached to a needle. The needle is usedto thread the open fastener through the stitches, while the releasemechanisms separates the fastener from the needle and allows thefastener to assume a closed configuration having the shape of thestitches.

In another aspect of the invention, a locking device is provided forreleasably locking the fastener in its open configuration. Upon releaseof the locking device a restraining force is removed from the fastenerto allow the fastener to move to its unbiased, closed position.Advantageously, the locking device may also be arranged to removablyconnect a needle to the fastener. Upon release of the locking device,the needle is disconnected from the fastener. Both removal of the needleand release of the biasing force from the fastener may occursimultaneously.

In yet another aspect of the invention, the fastener includes a wirewhich, in one embodiment has a circular cross-section, and in anotherembodiment is a shape memory alloy.

A method of the present invention generally includes inserting afastener through tissue with the fastener biased in an open position bya restraining device coupled to the fastener, and removing therestraining force on the fastener to allow the fastener to close. In oneembodiment the fastener is maintained in an open configuration by alocking device and returns to a closed configuration upon release of thelocking device.

Yet another aspect of the present invention provides a method of using afastener to form multiple stitches. A self-closing fastener having agenerally open configuration and a closed configuration in the form of aspecified number and spacing of multiple stitches is provided. Thefastener is stitched, through an attachment to a needle, through thespecified stitches. The fastener is then actuated to allow theconfiguration to assume a closed configuration.

The above is a brief description of some deficiencies in the prior artand advantages of the present invention. Other features, advantages, andembodiments of the invention will be apparent to those skilled in theart from the following description, accompanying drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a tissue connector assembly of the presentinvention;

FIG. 2A shows a graft vessel connected to a target vessel with tissueconnector assemblies of FIG. 1;

FIG. 2B is a front view of the connected graft and target vessels ofFIG. 2A, with portions broken away to show detail;

FIG. 2C is an enlarged view of the tissue connection shown in FIG. 2B;

FIGS. 3A-3D are enlarged views of a fastener of the tissue connectorassembly of FIG. 1, where FIG. 3A shows the fastener in a closedposition, FIG. 3B is a side view of the fastener of FIG. 3A, FIG. 3C isan enlarged view of the fastener in an open position, and FIG. 3D is anenlarged view of an alternate configuration of the fastener shown in aclosed position;

FIGS. 3E-3G are enlarged views of an alternate configuration of thefastener of the tissue connector assembly of FIG. 1, where FIG. 3E showsthe fastener in a closed position, FIG. 3F is a side view of thefastener of FIG. 3E, and FIG. 3G is an enlarged view of an alternateconfiguration of the fastener shown in a closed position;

FIGS. 4A-4C is are cross-sectional views of a restraining device of thetissue connector assembly of FIG. 1, where FIG. 4A is a view of theassembly in a locked position, FIG. 4B is a cross-sectional view of therestraining device of FIG. 4A taken in the plane including line 4B—4B,and FIG. 4C is a cross-sectional view of the restraining device of FIG.4A in an unlocked position;

FIG. 5 is an alternate embodiment of the restraining device of FIG. 4A;

FIG. 6 is a perspective of a second embodiment of a tissue connectorassembly of the present invention;

FIG. 7 shows two tissue connector assemblies of FIG. 6 in a first stepfor connecting a graft vessel to a target vessel;

FIG. 8 shows a second step for connecting the graft vessel to the targetvessel;

FIG. 9 shows a third step for connecting the graft vessel to the targetvessel;

FIG. 10 shows an alternate method for connecting the graft vessel to thetarget vessel with the tissue connector assemblies of FIG. 6;

FIG. 11 is a front view of a single-arm tissue connector assembly havinga multiple loop fastener of the present invention;

FIGS. 12A-12F illustrates yet another restraining device, where FIG. 12Ashows a perspective view of the restraining device coupled with afastener of FIG. 1, FIG. 12B is a sectional view of the restrainingdevice of FIG. 12A, FIG. 12C is a transverse cross-sectional view of therestraining device taken along line 12C—12C in FIG. 12B, FIG. 12D showsa perspective view of the restraining device coupled with a fastener ofFIGS. 6 or 11, FIGS. 12E and 12F are perspective and end views of therestraining device, respectively, showing the device depressed forrelease of the fastener;

FIG. 13A-13D are front views of four alternate multiple loop fastenerembodiments of the present invention in the closed configuration, whereFIG. 13A has evenly spaced loops, FIG. 13B includes both evenly andunevenly spaced loops, and FIGS. 13C and D are details of fasteners ofFIG. 13A and B, respectively, configured for use in a double-arm tissueconnector assembly;

FIG. 14A-14C illustrates the use of the assembly of FIG. 11 inconnecting tissue, where FIG. 14A shows the orientation of the tissuesand the first piercing, FIG. 14B shows the threading of the fastenerthrough the tissues, and FIG. 14C is a released fastener in the closedconfiguration of FIG. 13A;

FIG. 15 is a front view of a double-arm tissue connector assembly havinga multiple loop fastener of the present invention;

FIGS. 16A-16C show a synchronized fastener release system, where FIGS.16A and 16C are partial sectional views of the system in a coupled anddecoupled state, respectfully, and FIG. 16B is a sectional view takenalong lines 16B—16B in FIG. 16A;

FIGS. 16D-16F show another synchronized fastener release system whereFIGS. 16D and 16E are partial sectional views of the system in a coupledand decoupled state, respectfully, and FIG. 16F is a transversecross-sectional view taken along line 16F—16F in FIG. 16E;

FIG. 16G shows yet another synchronized fastener release system in thecoupled state for use on a double-arm tissue connector as in FIG. 15;and

FIG. 17A-17D illustrates the use of the double-arm tissue connectorassembly of FIG. 15 in connecting tissue, where FIG. 17A shows theorientation of the tissues and the piercings of the first needle, FIG.17B shows the threading of the fastener through the tissues and thepiercings of the second needle, FIG. 17C shows the fastener afterthreading through the tissue, and FIG. 17D is a released fastener in theclosed configuration of FIG. 13A.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DESCRIPTION OF THE INVENTION

Referring now to the drawings, and first to FIG. 1, a tissue connectorassembly constructed according to the principles of the presentinvention is shown and generally indicated with reference numeral 1. Thetissue connector assembly 1 may be used to manipulate and align tissues,or tissue and graft with respect to each other and thereafter connectthe tissues together (FIGS. 2A-2C, 7-10, 14 and 17). As used herein, theterm graft includes any of the following: homografts, xenografts,allografts, alloplastic materials, and combinations of the foregoing.The tissue connector assembly 1 may be used in vascular surgery toreplace or bypass a diseased, occluded, or injured artery by connectinga graft vessel 12 to a coronary artery 14 or vein in an anastomosis, forexample. The tissue connector assembly 1 may be used in open surgicalprocedures or in minimally invasive or endoscopic procedures forattaching tissue located in the chest, abdominal cavity, orretroperitoneal space. These examples, however, are provided forillustration and are not meant to be limiting.

In the embodiment shown in FIG. 1, the tissue connector assembly 1generally comprises a penetrating member 2, and fastener or surgicalclip 10. A restraining device, generally indicated at 8 and comprising aspring (or coil) 26 and a locking device generally indicated at 4, isconnected to the fastener 10 for holding the fastener in a deformedconfiguration as further described below. Activation of the restrainingdevice 8 produces two effects: it allows fastener 10 to becomeunrestrained, allowing it to assume a differently, or undeformed,configuration, and acts as a release mechanism to separate fastener 10from penetrating member 2.

The penetrating member or needle 2 has a sharp pointed tip 30 at itsdistal end for penetrating tissue. The needle 2 may be bent as shown inFIG. 1, for example. The distal end of the needle 2 is preferably rigidto facilitate penetration of tissue. The remaining length of the needle2 may be rigid or flexible to facilitate movement of the needle throughthe tissue as further described below. The tip 30 of the needle 2 may beconical, tapered, or grounded to attain a three or four facet tip, forexample. The needle 2 may be made from stainless steel or any othersuitable material, such as a polymeric material. It is to be understoodthat the needle 2 may have a shape or radius of curvature other than theone shown, without departing from the scope of the invention. The needle2 may be integrally formed with the locking device 4 or may be swaged,welded, threadably attached, or attached by any other suitable means tothe locking device.

As shown in FIG. 3A, one embodiment of a fastener 10 comprises adeformable wire 34 made of a shape memory alloy. A nickel titanium(nitinol) based alloy may be used, for example. The nitinol may includeadditional elements which affect the yield strength of the material orthe temperature at which particular pseudoelastic or shapetransformation characteristics occur. The transformation temperature maybe defined as the temperature at which a shape memory alloy finishestransforming from martensite to austenite upon heating (i.e., A_(f)temperature). The shape memory alloy preferably exhibits pseudoelastic(superelastic) behavior when deformed at a temperature slightly aboveits transformation temperature. At least a portion of the shape memoryalloy is converted from its austenitic phase to its martensitic phasewhen the wire is in its deformed configuration. As the stress isremoved, the material undergoes a martensitic to austenitic conversionand springs back to its original undeformed configuration. When the wire34 is positioned within the tissue in its undeformed configuration, aresidual stress is present to maintain the tissue tightly together (FIG.2C). In order for the pseudoelastic wire 34 to retain sufficientcompression force in its undeformed configuration, the wire should notbe stressed past its yield point in its deformed configuration to allowcomplete recovery of the wire to its undeformed configuration. The shapememory alloy is preferably selected with a transformation temperaturesuitable for use with a stopped heart condition where cold cardioplegiahas been injected for temporary paralysis of the heart tissue (e.g.,temperatures as low as 8-10 degrees Celsius).

It is to be understood that the shape memory alloy may also be heatactivated, or a combination of heat activation and pseudoelasticproperties may be used, as is well known by those skilled in the art.

The cross-sectional diameter of the wire 34 and length of the wire willvary depending on the specific application. The diameter “d” of the wire34 may be, for example, between 0.001 and 0.015 inch. For coronarybypass applications, the diameter is preferably between 0.001 and 0.008inch with a diameter “D” of the loop being between 0.0125 and 0.0875inch (FIG. 3A). The diameter “D” of the loop of the fastener 120 in itsclosed position is preferably sized to prevent movement between adjacenttissues. As shown in FIG. 3A, the wire 34 has a circular cross-sectionalshape. It is to be understood that the wire may have othercross-sectional shapes such as rectangular, or may be formed frommultiple strands without departing from the scope of the invention.

The proximal end of the wire 34 may include a stop 36 having across-sectional area greater than the cross-sectional area of the wireand coil 26 to prevent the wire and coil from passing through the tissue(FIG. 3C). The stop 36 may be attached to the end of the wire 34 bywelding, gluing or other suitable attachment means or may be formedintegrally with the wire by deforming the end of the wire. There areseveral embodiments of stop 36 that provide for different uses orapplications of the inventive fasteners. Thus in one embodiment, thestop 36 may be large enough to prevent the proximal end of wire 34 frombeing pulled through the tissue. In another embodiment, the stop mayprovide coupling to additional flexible members or needles, as describedbelow and in copending patent application Ser. No. 09/260,623. In yetanother embodiment, the stop 36 may be eliminated to facilitate pullingthe fastener completely through the tissue, if, for example, the entirefastener needs to be removed from the vessel during the insertionprocedure. The distal end of the wire 34 includes an enlarged portion 38for engagement with one of the restraining devices 8 as furtherdescribed below (restraining devices 8 a in FIG. 4A and 8 c in FIG.12A), or other equivalent structures. The enlarged portion 38 may beformed by deforming the end of the wire 34 by swaging or arc welding, orattaching by welding, swaging, or other suitable means to form anenlarged portion at the end of the wire.

The wire 34 has an undeformed or closed position (state orconfiguration) for keeping or connecting tissue together, and a deformedor open position (state or configuration) for insertion of the wire intotissue, and is moved from its closed position to its open position byone of the restraining devices 8, as further described below. The wire34 is preferably not deformed past its yield point in its open position.Accordingly, one embodiment provides a U-shaped configuration for anopen position to facilitate insertion of the wire 34 through the tissue.It is to be understood that a U-shaped configuration may bealternatively substituted by an equivalent structure such as C-shaped,V-shaped, J-shaped, and other similarly shaped configurations. When inits closed position, the wire 34 of the first embodiment forms a loopwith the ends of the wire in a generally side-by-side or overlappingorientation (FIG. 3B).

The wire 34 may be formed in the above described shape by first wrappingthe wire onto a mandrel and heat treating the wire at approximately400-500 degrees Celsius for approximately 5 to 30 minutes. The wire 34is then air quenched at room temperature. The mandrel may have aconstant diameter, may be conical in shape, or may have other shapes fortreating a wire into a shape useful for producing a fastener.

An alternate configuration of the surgical fastener 10 in its closedposition is shown in FIG. 3D, and generally indicated at 40. Thefastener 40 forms a spiral configuration in its closed position fortrapping tissue within a loop formed by the spiral. In its openposition, the fastener 40 is configured to form less than a full 360degree turn.

Another alternate configuration of the surgical fastener 10 is shown inFIGS. 3E and 3F in its closed position, and is generally indicated at41. The fastener 41 is formed in a spiral about a central longitudinalaxis A. As shown in FIG. 3F, the fastener 41 has a generally conicalshape along the longitudinal axis A, with a decreasing diameter as theradius of curvature of the fastener 41 decreases. The fastener 41 has aninner end portion 45 and an outer end portion 47, with the enlargedportion 38 of the wire being disposed at the outer end portion forengagement with one of the restraining devices 8.

A modification of the fastener is shown in FIG. 3G, and generallyindicated at 43. The fastener 43 is same as the fastener 41 describedabove, except that the enlarged portion 38, which is adapted forengaging a restraining device or releasable mechanism, is positioned atthe inner end portion 45 of the fastener. Placement of one of therestraining devices 8 at the inner end portion 45 of the fastener 43increases the compression force of the wire in its undeformed positionon the tissue and decreases the surface area of the fastener exposed toblood flow.

A second embodiment of wire 34, as shown in an open configuration inFIG. 11 and in a closed configuration in FIGS. 13A-13B. Specifically,FIG. 11 shows a front view of a single-arm tissue connector assembly1101 having a multiple loop fastener in an open configuration, andgenerally indicated as 1300. FIG. 13A shows a particular multiple loopfastener 1301 having evenly spaced loops in a closed configuration, andFIG. 13B shows another particular multiple loop fastener 1303 havingboth evenly and unevenly spaced loops in a closed configuration. Themultiple loop fasteners 1301 and 1303 are similar to the previouslydescribed fasteners 10, 40, 41, and 43, with the wire 34 specificallypreformed as a spiral of more than one loop.

As shown if FIG. 13A, the loops of fastener 1301 are helical with acenterline B, and form slightly less than two complete loops. Theenlarged portion 36 is preferably large enough to prevent coil 26 frommoving off the proximal end of wire 34. In one embodiment, the distalend of wire 34 is configured to be threaded through a tissue, and theenlarged portion 36 is large enough to prevent the proximal end of wire34 from being pulled through the tissue. As shown in FIG. 13B is themultiple loop fastener 1300 having both evenly and unevenly spacedloops, and generally indicated at 1303. The loops of fastener 1303 areformed on the surface on a cylinder having a centerline C. As withfastener 1301, the enlarged portion 36 is preferably large enough toprevent coil 26 from moving off the proximal end of wire 34. Also, aswith fastener 1301, the distal end of wire 34 may be configured forthreading through a tissue, with the enlarged portion 36 large enough toprevent the proximal end of wire 34 from being pulled through thetissue.

It is to be understood that the fastener 10, 40, 41, 43, 1300 and otherfasteners described herein may have undeformed or deformedconfigurations different than those shown herein without departing fromthe scope of the invention. In addition, a locking clip (not shown) mayalso be attached to connect the ends of the fasteners of this inventionwhen the fastener is in its closed position to prevent possible openingof the fastener over time. The locking clip may also be integrallyformed with one end of the fastener.

The wire 34 of any of the fasteners of the present invention, as shownfor example in FIG. 3A-3C, may be surrounded by the spring or coil 26which, along with the locking device 4 a , restrains the wire in itsdeformed configuration. The coil 26 comprises a helical wire forming aplurality of loops which define a longitudinal opening 44 for receivingthe shape memory alloy wire 34. The coil 26 may be formed from aplatinum alloy wire having a cross-sectional diameter of approximately0.0005-0.005 inch, for example. The wire may have other cross-sectionalshapes and be formed of different materials. The coil 26 is preferablysized so that when in its free (uncompressed state) it extends thelength of the wire 34 with one end adjacent the stop 36 at the proximalend of the wire and the other end adjacent the enlarged portion 38 atthe distal end of the wire (FIG. 3B). It is to be understood that thespring 26 may not extend the full length of the wire. For example, aflange or similar device may be provided on an intermediate portion ofthe wire 34 to limit movement of the coil along the length of the wire.

When the coil 26 is in its free state (with the wire 34 in itsundeformed configuration), loops of the coil are generally spaced fromone another and do not exert any significant force on the wire 34 (FIG.3A). When the coil 26 is compressed (with the wire 34 in its deformedconfiguration), loops of the coil on the inner portion 46 of the coilare squeezed together with a tight pitch so that the loops are near orcontiguous with one another while loops on the outer portion 48 of thecoil are spaced from one another (FIG. 3C). This is due to thecompressed inner arc length of the coil 26 and the expanded outer arclength of the coil. The compression of the loops on the inner portion 46of the coil 26 exerts a force on the inner side of the wire 34 whichforces the wire to spread open (i.e., tends to straighten the wire fromits closed configuration to its open configuration). The end of the coil26 adjacent the stop 36 is held in a fixed position relative to the wire34. The opposite end of the coil 26 is free to move along the wire 34and is held in place when the coil is in its compressed position by thelocking device 4 a (FIG. 4A).

The locking device 4 a shown in FIGS. 4A-4C comprises a flexible tubularmember 50 having a distal end portion 52 coupled to a needle 2 and aproximal end portion 54 releasably attached to the wire 34. The tubularmember 50 is movable between a locked position (FIG. 4A) for holding thecoil 26 in its compressed position and the wire 34 in its deformedposition, and an unlocked position (FIG. 4C) for inserting or releasingthe wire and coil. Three slots 58 are formed in the tubular member 50extending from the proximal end 54 of the member and along at least aportion of the member (FIGS. 4B and 4C). The slots 58 are provided toallow the proximal end 54 of the tubular member 50 to open for insertionand removal of the wire 34 when the tubular member is in its unlockedposition (FIG. 4C). It is to be understood that the number of slots 58and configuration of the slots may vary.

The proximal end 54 of the tubular member 50 includes a bore 62 having adiameter slightly greater than the outer diameter d of the wire 34, butsmaller than the diameter of the enlarged portion 38, and smaller thanthe outer diameter of the coil 26. The bore 62 extends into a cavity 64sized for receiving the enlarged portion 38 of the wire 34. Member 50may be described as having an annular flange 61 for releasably securingthe enlarged portion 38. As shown in FIG. 4C, upon application of aninwardly directed radial squeezing force on the tubular member 50 theproximal end 54 of the tubular member is opened to allow for insertionor removal of the wire 34. When the force is released (FIG. 4A), thetubular member 50 moves back to its locked position and securely holdsthe wire 34 in place and compresses the coil 26. A disc 51 may beinserted into the tubular member 50 to act as a fulcrum and cause theproximal end 54 of the tubular member to open upon application of forceon the tubular member. Alternatively, the disc 51 may be integrallyformed with the tubular member 50. As shown in FIG. 4A, the length l ofthe bore 62 or flange 61 determines the amount of compression of thecoil, which in turn determines the amount of deformation of the wire 34.The greater the length l of the bore 62, the greater the compression ofthe coil 26 and the more straightening the wire 34 will undergo. Thecompression of the coil 26 is preferably limited so that the wire 34 isnot stressed beyond its yield point. This allows the wire 34 to revertback to its original undeformed configuration and apply sufficientpressure to hold the connected tissue together.

An alternate embodiment of the restraining device is shown in FIG. 5,and generally indicated with reference numeral 8 b. The restrainingdevice 8 b is used with a tubular (hollow) shape memory alloy wire ortube 72 and comprises an elongated member (or mandrel) 74 sized forinsertion into the wire. The mandrel 74 is preferably formed from amaterial which is stiffer than the material of the wire 72 so that uponinsertion of the mandrel into the wire, the wire is deformed into itsopen position. The restraining device 8 b includes a stop 76 located atthe proximal end of the wire 72. The stop operates to prevent thefastener from being pulled through the tissue, and limits axial movementof the mandrel 74 in the proximal direction (to the right as viewed inFIG. 5). The distal end of the mandrel 74 is releasably attached to theneedle 2.

Yet another alternate embodiment of the restraining device, generallyindicated with reference numeral 8 c, and locking device, generallyindicated with reference numeral 4 c, is shown in FIG. 12. Specifically,FIGS. 12A-12E illustrate a release mechanism or restraining device whichis disclosed in U.S. patent application Ser. No. 09/259,705, filed onMar. 1, 1999 and entitled Tissue Connector Apparatus With Cable Release.FIGS. 12A-C show the mechanism coupled with a fastener, and FIGS. 12Dand 12E show the release mechanism depressed for release of thefastener. Restraining device 8 c comprises a plurality of substantiallyrigid strands, preferably wires 106, arranged substantially parallel toone another and circularly about a longitudinal axis of the alignedstrands, to form a tube-like configuration, as can be seen in thecross-sectional view of FIG. 12C and the perspective view in FIG. 12A.Restraining device 8 c has a distal end portion 106 a that can becoupled to needle 2 and a proximal end portion 106 b releasably attachedto the wire 34. Alternatively, strands 106 may be cables or some othersubstantially rigid strand elements arranged in the same manner as thewires shown in FIG. 12C.

Preferably, a rod 162 extends into distal end portion 106 a tofacilitate fixation of the strands thereto, as shown in FIG. 12B. Thecoupling of the strands to needle 2 is preferably accomplished by gluingor soldering to rod 162, although other equivalent or similar knownjoining techniques may be employed (e.g. welding, threadably attaching,etc). Similarly, rod 162 is preferably glued, soldered or threaded intothe needle.

The end portions 106 b of the strands in the vicinity of the fastenerstrands include notches 109 which are formed into the strands to a depthequal to approximately half the diameter of the strand 106. When thestrands are arranged in the circular configuration described above, thenotches 109 form a chamber 108 configured for receiving and holdingenlarged portion 38. Although enlarged portion 38 is shown as having aspherical shape, it may have other shapes including a barrel shape, orother shape that may be easily grasped and easily released. The notchesare preferably placed about 0.015″ from the free ends of the strands,but this distance, of course, can be modified, depending upon the amountof compression of spring 26 that is desired when ball 38 is insertedinto and held by notches 109.

After placement of ball 38 within chamber 108 formed by notches 109, ashrink wrap layer, preferably a shrink tubing 105 may be provided overat least free end portions 106 b of wires or strands 106, and the tubingheated to compress against strands 106 and hold them in place againstball 38, preferably symmetrically against ball 38. Together, tubing 105and strands 106 effectively hold ball 38 captive within notches 109,acting as locking mechanism 4. Alternatively, other plastic or elasticrestraining members may be mounted around the distal portions of thewires or strands to aid in maintaining them in place, preferablysymmetrically against ball 38. Still further, strand members may bedesigned with an elastic spring force sufficient to maintain notches 109in place with sufficient force to maintain the ball 38 captive thereinunder the tensile forces normally experienced during a suturingprocedure. Although a seven-strand embodiment is shown, it should beunderstood that fewer or more than seven strands may be used. The numberof strands may vary depending on, for example, the size of the fasteneror the size of the strands. Typically, the number of strands may rangefrom two to ten. In a coronary anastomosis, the number of strandspreferably will range from five to seven although other numbers may beused.

In assembling, enlarged portion 38 of vire 34 is placed in chamber 108.Tubing 105 is wrapped around at least a portion of the strands (as shownin the drawings) and heated to maintain enlarged portion 38 captivewithin the cavity formed by the strands. Compression coil or spring 26is slid over wire 34 and compressed against portions 106 b such that thefastener is in its open configuration. Enlarged portion 36 may then beformed or attached to wire 34 to maintain the fastener in its openconfiguration.

Locking device 4 c is movable between a locked position (FIGS. 12A-12C)and an unlocked position (FIGS. 12E and 12F). In the locked position theball 38 is held within notches 109 and consequently, coil 26 is held inits compressed position, thereby maintaining fastener wire 34 in itsdeformed or open position. In the unlocked position, ball 38 is releasedfrom the notches, thereby allowing the coil 26 to expand, which causesthe fastener wire 34 to close. The closure conformation of the wire maybe characterized by any of those described above with reference to FIG.3 or the subsequently described FIGS. 13, for example.

Movement of the locking mechanisms 4 c, and thus release of restrainingdevice 8 c, to the open position is accomplished by applying acompressive force to the shrink tube 105 and bundle of strands 106, asshown in FIGS. 12E and 12F. Advantageously, the compressive force may beapplied at any opposing locations around the circumference of the shrinktube as long as the implement applying the force is oriented at an angleto the strands, preferably substantially perpendicular thereto, to allowthe implement to traverse the strands so as to deform the positionsthereof when the force is applied. For example, needle holder 111 couldbe rotated 90° (or virtually any other angle) with respect to thestrands 106 as shown in the plane of the drawing, while retaining thecapability of deforming the strands to an open position upon applicationof a compressive force. The compressive force is preferably appliedusing a standard needle holder 111 or forceps, although other toolscould be used, preferably those with applicators narrower than thelength of the shrink tube 105. As shown, the strands or wires 106 getdistorted from their circular configuration under the compression. Thischange in shape stretches the shrink tube 105 from a circularconfiguration to a somewhat elliptical configuration, and removes someof the notches 109 from contact with ball 38, thereby permitting removalof ball 38 from within the chamber previously formed by notches 109 inthe closed position. It is to be understood that in addition to therestraining devices disclosed herein, other types of restraining devicesmay be used without departing from the scope of the invention.

It is to be understood that locking devices other than those describedabove may be used without departing from the scope of the invention. Forexample, a locking device (not shown) may comprise a tubular memberhaving an opening formed in a sidewall thereof for receiving an endportion of the wire. The end of the wire may be bent so that it isbiased to fit within the opening in the sidewall of the tubular member.An instrument, such as a needle holder may then be used to push the wireaway from the opening in the tubular member and release the wire fromthe tubular member. Various other types of locking devices including aspring detent or bayonet type of device may also be used.

Another embodiment of the tissue connector assembly is shown in FIG. 6and generally indicated with reference numeral 110. The tissue connectorassembly 110 is similar to the tissue connector assembly 1 of the firstembodiment, except that a flexible member 118 is inserted between arestraining device 124 a and needle 116. FIG. 6 shows the tissueconnector assembly 110 with a fastener 120 in an open (deformed)position. The fastener 120 may be the same as the fasteners 10, 40, 41,43 described above and shown in FIGS. 3A-3G for the tissue connectorassembly 1 of the first embodiment, for example. The fastener 120includes the restraining device 124 a comprising a coil 126 and alocking device 128 a. The locking device 128 a and the restrainingdevice 124 a are similar to those described above and shown in FIGS.4A-4C, except that the distal end is configured for attachment to theflexible member 118. An alternative locking device 128 c and arestraining device 124 c, similar to those described in FIGS. 12A-12C,are shown attached to the flexible member 118.

The flexible member 118 is attached to the distal end of the lockingdevice 128 with a tapered portion or transition sleeve 156 extendingfrom the locking device to the flexible member 118 to facilitateinsertion of the locking device through tissue. The tapered sleeve 156is preferably sufficiently curved to facilitate movement of the tissueconnector assembly 110 through connecting tissue in an anastomosis, forexample. The sleeve 156 may be formed from a metal alloy such asstainless steel or a suitable polymeric material. The needle 116 may beswaged into the sleeve 156, or a heat shrink plastic covering may holdthe needle in place. The locking device 128 may also be curved.

The flexible member 118 may be in the form of a suture formed fromconventional filament material, metal alloy such as nitinol, polymericmaterial, or any other suitable material. The material may benon-stretchable or stretchable, solid or hollow, and have variouscross-sectional diameters. The suture may have a cross-sectionaldiameter of 0.003 inch, for example. The diameter and length of thesuture will vary depending on the specific application. The suture maybe attached to the needle 116 by crimping or swaging the needle onto thesuture, gluing the suture to the needle, or any other suitableattachment method. The flexible member 118 may have cross-sectionalshapes other than the one shown herein.

The needle 116 may be integrally formed with the flexible member 118.The diameter of at least a portion of the needle 116 is preferablygreater than the diameter of the flexible member 118 so that theflexible member can easily be pulled through an opening formed in thetissue by the needle.

Another embodiment of the tissue connector assembly is shown in FIG. 11,and generally indicated with reference numeral 1101. FIG. 11 shows thetissue connector assembly 1101 with a fastener 1300 in an open(deformed) position. The tissue connector assembly 1101 is similar tothe tissue connector assembly 110, the major difference being theattachment of a multiple loop fastener 1300 to flexible member 118. Theloops may be helical, spiral, or have other looping shapes, includingvariations in loop shape from loop-to-loop and changes in shape alongthe loop to aid in the clipping functions discussed subsequently. Theloops may also have bends or turns at the wire 34 ends. FIG. 11 showsthe tissue connector assembly 1101 with a fastener 1300 in an open(deformed) position. The fastener 1300 includes the restraining device124 c comprising a coil 26 and a locking device 128 c. The transitionfrom the distal end portion 106 a of restraining device 124 c is shownin FIG. 12D. Alternatively, the restraining device 124 a and lockingdevice 128 a could be substituted for those in the embodiment of FIG.11.

Yet another embodiment of the tissue connector assembly is shown in FIG.15 as a double-arm tissue connector assembly, and generally indicatedwith reference numeral 1502. The double-arm tissue connector assembly1502 is a double-arm assembly, in which a multiple loop fastener 1506 isattached to two needles, 116′ and 116″. Previous disclosure of adouble-arm assembly attached to fasteners such as fastener 10, 40, 41,43 has been disclosed in copending patent application Ser. No.09/260,623, filed Mar. 1, 1999, of which this application is acontinuation-in-part.

In the embodiment of FIG. 15, a multiple loop fastener 1500 has two endsadapted to be connected to and released from a corresponding needle. Afirst fastener end 1500′ has restraining device 124 c and lockingmechanism 128 c, as in the distal end of the fasteners previouslydescribed for single needle use. The first fastener end 1500′ isattached to first needle 116′ through a first flexible member, such asflexible member 118′, which in turn is coupled to needle 116′. A secondfastener end 1500″ is attached to second needle 116″ through a flexiblemember such as second flexible member 118″. The second fastener end1500″ has a release mechanism 123 c for releasably coupling fastener1500 to flexible member 118″, as shown in FIG. 16G. In this arrangement,a member or stopper 115, which may be annular, is secured to the otherend of the fastener or wire 34 to prevent enlarged portion 36 frompassing through the compression spring upon release from releasemechanism 123 c. This arrangement thus allows for the activation oflocking mechanism 128 c to release both flexible members 118′ and 118″from fastener 1500.

Examples of double-arm fasteners are shown in FIGS. 13A-13D.Specifically, where FIG. 13A has evenly spaced loops, FIG. 13B includesboth evenly and unevenly spaced loops, and FIGS. 13C and D are detailsof fasteners of FIG. 13A and B, respectively, configured for use in adouble-arm tissue connector assembly. Fastener 1501 of FIG. 13C andfastener 1503 of FIG. 13D are modified versions of fasteners 1301 and1303, respectively, where the enlarged end 36 has been modified to workwith release mechanism 123 c, as in FIG. 16G. Thus FIG. 13C shows anevenly spaced loop, as in FIG. 13A, where a stopper 115 has been addedto the enlarged portion end 36, and FIG. 13D shows a combined evenly andunevenly spaced loop fastener with the enlarged portion suitablymodified.

Other combined release and restraining mechanisms, which providesynchronized release of both needles illustrated in FIG. 15, also can beused. FIGS. 16A-16F illustrate synchronized fastener release systems.Referring to FIGS. 16A-16C, a first synchronized release system is shownin a coupled and decoupled state, respectfully. Although one releasemechanism is shown as corresponding to restraining device 128 c andlocking device 124 c, any release mechanism which releasably couples theflexible member or needle to the surgical fastener and effectscompression of coil 26 also may be used. At the other end of thefastener or wire 34, a release mechanism that responds to thecompressive state of coil 26 and releases the fastener or wire 34 uponrelease of compressive forces on the coil is shown and generallydesignated with reference numeral 123 a. Release mechanism 123 acomprises two members 1601 each having a recess 122 formed therein andarranged to form chamber 1603 when members 1601 are aligned as shown inFIG. 16A. Recesses 122 are configured to retain enlarged portion 36,which is shown with a cylindrical configuration, but may have aspherical or other suitable shape for operatively associating with asuitably configured chamber. Further, members 1601 may have semicirculartransverse cross sections or some other combination of transverse shapesthat can collectively provide the desired chamber to retain enlargedportion 36. The number of members 1601 also may vary as would beapparent to one of ordinary skill.

Restraining device members 1601 have tapered ends 1605, which areconfigured for positioning between coil 26 and fastener wire 34 as shownin FIG. 16A. When tapered ends 1605 are so positioned and coil 26 is ina compressed state, coil 26 holds tapered ends 1605, which are normallybiased away from each other as shown in FIG. 16C, sufficiently togetherto retain enlarged portion 36 within chamber 1603. When locking device128 c is actuated (e.g., radially compressed to release enlarged portion38 of fastener wire 34, coil 26 assumes its relaxed state, therebyreleasing tapered ends 1605 of release mechanism 123 a from the coil andallowing the tapered ends to radially expand and release enlargedportion 36 of fastener wire 34 as shown in FIG. 16C. Accordingly, bothneedles and flexible members may be decoupled from the fastener whenrestraining device 123 a is actuated.

FIGS. 16D-16F show another synchronized fastener system that is the sameas the system shown in FIGS. 16A-16C with the exception of releasemechanism 123 b and the cooperating portion of the fastener or wire 34being substituted for release mechanism 123 a. In this embodiment, anannular member or stopper 115, which may be annular, is slidably coupledto fastener wire 34. Member 115 is configured to resist passage of coil26 thereover. Accordingly, member 115 may have an outer diameterslightly greater than at least the portion of the coil adjacent thereto.A tapered or frustoconical member 156′″ is secured to an end of fastenerwire 34, which need not include an enlarged portion. Member 156′″ is thesame as member 156″ with the exception that member 156′″ has a channel134 for receiving flexible member or suture 118″. Channel 134 extendsradially outward from bore 132, which is formed through member 156′″,for receiving the fastener or wire 34.

Flexible member 118″ is threaded through channel 134 and between taperedmember 156′″ and annular member 115. When coil 26 is in a compressedstate as shown in FIG. 16D, the coil urges member 115 toward taperedmember 156′″ and compresses flexible member 118″ therebetween. In thismanner, flexible member 118″ is secured to the fastener or wire 34. Whenlocking device 128 c is actuated (e.g., radially compressed) to releaseenlarged portion 38 of the fastener or wire 34, coil 26 assumes itsrelaxed state so that annular member 155 may slide away from taperedmember 156′″ and release flexible member 118″. Accordingly, both needlesand flexible members may be removed from the fastener when lockingdevice 128 c is actuated. Although a metal flexible member may be used,a polymeric flexible member may be preferred.

As noted above, the tissue connector assemblies 1, 110, 1101, and 1502of this invention have many uses. They may be especially useful inminimally invasive surgical procedures including creating an anastomosisbetween vascular graft 12 and artery 14 (FIGS. 2A-2C). The anastomosismay be used to replace or bypass a diseased, occluded or injured artery.A coronary bypass graft procedure requires that a source of arterialblood flow be prepared for subsequent bypass connection to a diseasedartery. An arterial graft may be used to provide a source of blood flow,or a free graft may be used and connected at the proximal end to asource of blood flow. Preferably, the source of blood flow is one of anynumber of existing arteries which may be dissected in preparation forthe bypass graft procedure. In many instances it is preferred to use theleft internal mammary artery (LIMA) or the right internal mammary artery(RIMA), for example. Other vessels which may be used include thesaphenous vein, gastroepiploic artery in the abdomen, radial artery, andother arteries harvested from the patient's body as well as syntheticgraft materials, such as DACRON® or GORETEX® (expandedpolytetrafluoroethylene). If a free graft vessel is used, the upstreamend of the dissected vessel, which is the arterial blood source, will besecured to the aorta to provide the desired bypass blood flow, as iswell known by those skilled in the art. The downstream end of the graftvessel is trimmed for attachment to an artery, such as the left anteriordescending coronary (LAD). It is to be understood that the anastomosismay be formed in other vessels or tissue.

In addition, assemblies providing multiple loop fasteners, such asassemblies 1101 and 1502, allow for forming more than one stitch perfastener. Tissue secured with a multiple stitch, self-closing fastenerhas many advantages over conventional suture. For example, it allows fora greater are of tissue to be connected per time. In addition, multipleloop fasteners 1300 or 1500 are more rigid and can be formed to providea greater closing force on the tissue than can be provided byconventional suture.

FIGS. 2A-2C and 7-9 show an exemplary use of the tissue connectorassemblies 1, 110 for connecting graft vessel 12 to artery 14 (targetvessel). In this example, two tissue connector assemblies 110 (FIG. 6)are used to make connections at generally opposite sides of the graftvessel and a plurality of tissue connector assemblies 1 (FIG. 1) areused to make connections between those made with tissue connectorassemblies 110. The procedure may be accomplished with a beating heartprocedure with the use of a heart stabilizer to keep the heart stable,for example. The procedure may also be performed endoscopically.

The patient is first prepped for standard cardiac surgery. Afterexposure and control of the artery 14, occlusion and reperfusion may beperformed as required. Referring to FIGS. 7-9, after the arteriotomy ofthe snared graft vessel 12 has been made to the appropriate length, atissue connector assembly 110 is attached to the free end of the graftvessel along an edge margin of the vessel. In order to attach theconnector assembly 110, the surgeon grasps the needle 116 with a needleholder (e.g., surgical pliers, forceps, or any other suitableinstrument) and inserts the needle 116 into an end margin of the graftvessel 12 in a direction from the exterior of the vessel to the interiorof the vessel. The surgeon then releases the needle 116 and grasps aforward end of the needle which is now located inside the graft vessel12 and pulls the needle and a portion of the suture 118 through thevessel. The needle 116 is passed through an opening 121 formed in thesidewall of the artery 14 and inserted into the tissue of the artery ina direction from the interior of the artery to the exterior of theartery. The surgeon then grasps the needle 116 located outside theartery 14 and pulls the needle and a portion of the suture 118 throughthe arterial wall. A second tissue connector assembly 110 may beinserted at a location generally 180 degrees from the location of thefirst tissue connector in a conventional “heel and toe” arrangement.Alternatively, a number of tissue connectors 110 may be insertedgenerally around the location of the heel. The graft vessel 12 may thenbe pulled towards the artery 14 to determine whether the opening 121formed in the sidewall of the artery is large enough before completingthe anastomosis.

Once the tissue connector assemblies 110 are inserted, the graft vessel12 is positioned above the opening 121 in the sidewall of the artery 14(FIG. 7). The fasteners 120 and needles 116 are pulled generally awayfrom the artery 14 to reduce the length of the suture 118 between thevessel 12 and artery and “parachute” the vessel onto the artery (FIG.8). The needles 116 are then pulled away from the artery 14 until thefastener 120 is positioned within the graft vessel 12 and artery withone end of each fastener extending from the vessel and the opposite endof each fastener extending from the artery (FIG. 9). The edges of thegraft vessel 12 and artery 14 are positioned adjacent one another toform a continuous interior and exterior surface along the matingportions of the vessel and artery. As shown in FIG. 2C, the tissue iscompressed within the fastener 120.

A surgical instrument (e.g., needle holder) is used to radially squeezeeach locking device 128 to release the locking device from the fastener120. Upon removal of the locking device 128, the coil 126 moves to itsfree uncompressed state which allows the wire 134 to return to itsoriginal undeformed closed position (FIG. 2A). As the wires 134 move totheir closed position the adjacent tissues of the graft vessel 12 andartery 14 which were previously pulled together during the parachutingof the graft vessel onto the artery, are squeezed together to securelyengage the graft vessel and artery (FIGS. 2B and 2C).

The tissue connector assemblies 1 are subsequently inserted atcircumferentially spaced locations around the periphery of the graftvessel 12 to sealingly fasten the graft vessel to the artery 14. Theneedle 2 of the fastener 1 is inserted into the graft vessel 12 from theexterior surface of the graft vessel and pushed through the graft vesseland artery 14 tissue. The needle holder is then used to pull the needle2 through the arterial wall. An instrument (same needle holder or othersuitable instrument) is used to apply a squeezing force to the lockingdevice 4 to release the wire 34 and coil 26 from the needle 2. Thisallows the coil 26 to move to its uncompressed configuration and thewire 34 to move to its closed position. It should be noted that thetissue connector assemblies 110 may remain in their open position whilethe tissue connector assemblies 1 are inserted into the tissue and movedto their closed position. The locking devices 128 of the tissueconnector assemblies 110 may subsequently be removed from the fasteners120 to allow the fasteners to move to their closed position. The numberand combination of tissue connectors assemblies 1, 110 required tosealingly secure the connecting tissues together may vary. For example,only tissue connector assemblies 1 may be used to complete the entireanastomosis, or only tissue connector assemblies 110 may be used toconnect tissues.

It should be noted that as the locking device 4 is squeezed two stepsare accomplished. The fastener 10 is released from the locking device 4,thus allowing the coil 26 to uncompress and the wire 34 to move to itsclosed configuration, and the needle 2 is released from the fastener.Thus, in the embodiment shown, the locking device 4 provides forsimultaneous actuating closure of the fastener 10 and release of theneedle 2 from the fastener.

The graft vessel 12 may also be parachuted onto the artery 14 in themethod shown in FIG. 10. The needles 116 are inserted into the graftvessel 12 and artery 14 as described above and the sutures 118 arepulled through the vessel so that the fasteners 120 are positionedwithin the vessel. The needles 116 are then pulled away from the artery14 to “parachute” the graft vessel 12 onto the artery.

Although the coil 126 is shown as remaining on the wire (FIG. 6), it isto be understood that the coil 126 may also be removed from the wire134, leaving only the wire in the connected tissue.

FIGS. 14 and 17 show exemplary uses of multiple loop tissue connectorassemblies 1101 and 1502, respectively, for connecting graft vessel 12to artery 14. In these examples, one tissue connector assembly 1101 or1502 is threaded through two stitches. The actual number and spacing ofstitches is determined by the preformed shape of multiple loop fastener1300 or 1500, and the surgeon must select the assembly 1101 or 1502 tomatch the type of stitch required. As discussed previously, the wire 34may also the shape of multiple, evenly spaced stitches or of widely orunevenly spaced stitches. The use of connector assemblies 1101 and 1502thus permits the rapid suturing of long attachment seems in anenvironment with limited space, such as is encountered in endoscopicsurgery. When the locking device 128 c is activated, the restrainingdevice 124 c provides for the wire 34 to assume a preformed shape of thetwo stitches. The wire secures the tissue without the need to tie off asuture, and release causes the flexible member 118 and needle 116 toseparate from the fastener for easy removal.

Preparation of the patient and artery 14 is similar to that described inreference to FIGS. 7-9. The surgeon selects a multiple loop fastener toexecute a specific suture. In the example of FIG. 14, a double stitch isperformed with a specially preformed double loop fastener 1301. The useof a single-arm multiple loop tissue connector assembly 1101, as shownin FIG. 11, in connecting tissue is illustrated in FIG. 14A-14C.Specifically, FIG. 14A shows the orientation of the tissues and thefirst piercing, FIG. 14B shows the threading of the fastener through thetissues, and FIG. 14C is a released fastener in the closed configurationof FIG. 13A; In order to attach the connector assembly 1301, as shown inFIG. 14, the surgeon performs two stitches with tissue connectorassembly 1101. FIG. 14A shows the first stitch, in which the surgeongrasps the needle 116 with a needle holder (e.g., surgical pliers,forceps, or any other suitable instrument) and inserts the needle 116into an end margin of the graft vessel 12 in a direction from theexterior of the vessel to the interior of the vessel. The surgeon thenreleases the needle 116 and grasps a forward end of the needle which isnow located inside the graft vessel 12 and pulls the needle and aportion of the suture 118 through the vessel. The needle 116 is passedthrough an opening 121 formed in the sidewall of the artery 14 andinserted into the tissue of the artery in a direction from the interiorof the artery to the exterior of the artery. The surgeon then grasps theneedle 116 located outside the artery 14 and pulls the needle and aportion of the suture 118 through the arterial wall. The enlarged end 36is large enough to prevent the pulling of the fastener 1301 through thegraft vessel 12 during attachment.

A second stitch is then performed with the tissue connector assembly1101, as shown in FIG. 14D. With both stitches threaded, the surgeonreleases locking device 128 c. The multiple loop fastener 1301 assumesthe shape of the double stitched fastener, and the needle 116 andflexible member 118 are removed. Specifically, a surgical instrument(e.g., needle holder) is used to radially squeeze locking device 128 cto release the locking device from the fastener 1301. Upon removal ofthe locking device 128 c, the coil 26 moves to its free uncompressedstate which allows the wire 34 to return to its original undeformedclosed position (FIG. 13A). As the wire 34 moves to the closed positionthe adjacent tissues of the graft vessel 12 and artery 14 are squeezedtogether to securely engage the graft vessel and artery (FIGS. 14C).

As before, it is noted that as the locking device 128 c is squeezed twosteps are accomplished. The fastener 1301 is released from the lockingdevice 128 c, thus allowing the coil 26 to uncompress and the wire 34 tomove to its closed configuration, and the flexible member 118 isreleased from the fastener. Thus, in the embodiment shown, the lockingdevice 128 c provides for simultaneous actuating closure of the fastener1301 and release of the flexible member 118 and needle 116 from thefastener.

The use of the double-arm, multiple loop fastener has some similaritieswith that of the single arm fastener. As before, the surgeon selects amultiple loop fastener to execute a specific suture. In the example ofFIG. 17, a double stitch is performed with a specially preformed doubleloop fastener 1501. The use of a double-arm multiple loop tissueconnector assembly 1502, as in FIG. 15, is illustrated for connectingtissue in FIG. 17. FIG. 17A shows the orientation of the tissues forpiercing with the first needle, FIG. 17B shows the orientation of thetissues for piercing with the second needle, FIG. 17C shows the tissueconnector assembly 1502 in place before release, and FIG. 17D shows themultiple loop fastener 1501 in the closed configuration.

In order to attach the connector assembly 1502, as shown in FIG. 17, thesurgeon performs one stitch with each needle 118 of tissue connectorassembly 1502. FIG. 17A shows the first stitch, in which the surgeongrasps the needle 116′ with a needle holder (e.g., surgical pliers,forceps, or any other suitable instrument) and inserts the needle 116′into an end margin of the graft vessel 12 in a direction from theexterior of the vessel to the interior of the vessel. The surgeon thenreleases the needle 116′ and grasps a forward end of the needle which isnow located inside the graft vessel 12 and pulls the needle and aportion of the suture 118′ through the vessel. The needle 116′ is passedthrough an opening 121 formed in the sidewall of the artery 14 andinserted into the tissue of the artery in a direction from the interiorof the artery to the exterior of the artery. The surgeon then grasps theneedle 116′ located outside the artery 14 and pulls the needle and aportion of the suture 118′ through the arterial wall.

A second stitch is then performed with the tissue connector assembly1502, as shown in FIG. 17B. The surgeon grasps the needle 116″ with aneedle holder (e.g., surgical pliers, forceps, or any other suitableinstrument) and inserts the needle 116″ through artery 14 near openingand in a direction from the exterior of the artery to the interior ofthe artery. The surgeon then releases the needle 116″ and grasps aforward end of the needle which is now located inside the artery 14. Thesurgeon pulls needle 116″ and a portion of the suture 118″ into artery14 and pierces an end margin of graft vessel 12. The surgeon thenreleases the needle 116″ and grasps a forward end of the needle which isnow located inside the graft vessel 14.

Both of needles 116″ and 116″ are pulled to located fastener 1501 asshown in FIG. 17C. The multiple loop fastener 1501 assumes the shape ofthe double stitched fastener, and the needles 116 and flexible members118 are removed. Specifically, a surgical instrument (e.g., needleholder) is used to radially squeeze locking device 128 c to release thelocking device from the fastener 1501. Upon removal of the lockingdevice 128 c, the coil 26 moves to its free uncompressed state whichallows the wire 34 to return to its original undeformed closed position(FIG. 13A). As the wire 34 moves to the closed position the adjacenttissues of the graft vessel 12 and artery 14 are squeezed together tosecurely engage the graft vessel and artery (FIGS. 14C).

As before, it is noted that as the locking device 128 c is squeezed twosteps are accomplished. The fastener 1501 is released from the lockingdevice 128 c, thus allowing the coil 26 to uncompress and the wire 34 tomove to its closed configuration, and flexible members 118 are releasedfrom the fastener. Thus, in the embodiment shown, the locking device 128c provides for simultaneous actuating closure of the fastener 1501 andrelease of the flexible member 118 and needle 116 from the fastener.

Although the suturing procedure has been described for an end-to-sideanastomosis, it should be appreciated that the procedure is applicableto an end-to-end and side-to-side anastomosis, connecting various tissuestructures including single and multiple tissue structures, and puncturesites, and connecting tissue to a prosthetic graft or valve, forexample.

It will be observed from the foregoing that the tissue connectorassemblies of the present invention have numerous advantages.Importantly, the assemblies are easier and faster to apply thanconventional sutures which require tying multiple knots. The assembliesmay be used in minimally invasive procedures including endoscopicprocedures, and may be inserted single handedly.

All references cited above are incorporated herein by reference.

The above is a detailed description of a particular embodiment of theinvention. It is recognized that departures from the disclosedembodiment may be made within the scope of the invention and thatobvious modifications will occur to a person skilled in the art. Thefull scope of the invention is set out in the claims that follow andtheir equivalents. Accordingly, the claims and specification should notbe construed to unduly narrow the full scope of protection to which theinvention is entitled.

1. A tissue connector assembly comprising: a fastener, where saidfastener is self-closing and is movable between an open configurationand a closed configuration having a shape of two or more stitches; andat least one restraining device, where said at least one restrainingdevice is coupled to said fastener for restraining said fastener towardssaid open configuration, further comprising a suture and at least oneneedle releasable attached to said fastener through said suture.
 2. Thetissue connector assembly of claim 1, wherein, when said at least onerestraining device is uncoupled, said fastener moves from said openconfiguration towards said closed configuration.
 3. The tissue connectorassembly of claim 1, wherein at least a portion of said restrainingdevice remains on said fastener when said needle is released from saidfastener.
 4. The tissue connector assembly of claim 1, wherein saidfastener comprises a wire.
 5. The tissue connector assembly of claim 4,wherein said wire has a generally circular cross-section.
 6. The tissueconnector assembly of claim 4 wherein said wire comprises shape memorymaterial.
 7. The tissue connector assembly of claim 1, wherein said atleast one restraining device is a restraining device, wherein saidfastener has a first end portion, a second end portion and an elongatedmember therebetween, said first end portion being coupled to saidmechanical restraining device, said second end portion having across-sectional area greater than a cross-sectional area of saidelongated member.
 8. The tissue connector assembly of claim 7, furthercomprising a needle releasably attached to said fastener, wherein atleast a portion of said restraining device remains on said fastener whensaid needle is released from said fastener.
 9. The tissue connectorassembly of claim 1, wherein said at least one restraining deviceincludes a first restraining device and a second restraining device,wherein said fastener has a first end portion, a second end portion andan elongated member therebetween, said first end portion being coupledto said first restraining device, and said second end portion beingcoupled to said second restraining device.
 10. The tissue connectorassembly of claim 1 wherein said fastener is in a relaxed state when insaid closed configuration.
 11. The tissue connector assembly of claim 1wherein said restraining device comprises a coil surrounding at least aportion of said fastener.
 12. The tissue connector assembly of claim 11wherein said coil comprises a plurality of adjacent loops, said coilbeing compressible with said plurality of adjacent loops being spacedcloser to one another along one side of said coil than along an oppositeside of said coil.
 13. A tissue connector assembly comprising: afastener, where said fastener is self-closing and is movable between anopen configuration and a closed configuration having a shape of two ormore stitches; and at least one restraining device, where said at leastone restraining device is coupled to said fastener for restraining saidfastener towards said open configuration, wherein said at least onerestraining device includes a first restraining device and a secondrestraining device, wherein said fastener has a first end portion, asecond end portion and an elongated member therebetween, said first endportion being coupled to said first restraining device, and said secondend portion being coupled to said second restraining device, furthercomprising a first needle releasably attached to said first end portionand a second needle releasably attached to said second end portion,wherein at least a portion of each of said at least one restrainingdevice remains on said fastener when each of said needles is releasedfrom said fastener.
 14. A tissue connector assembly comprising: afastener, where said fastener is self-closing and is movable between anopen configuration and a closed configuration having a shape of two ormore stitches; and at least one restraining device, where said at leastone restraining device is coupled to said fastener for restraining saidfastener towards said open configuration wherein said restraining devicecomprises a coil surrounding at least a portion of said fastener whereineach of said at least one restraining device includes a lock releasablyengaging said coil, wherein engagement of said lock with said coilbiases said fastener in said open configuration.